Why does an injection molded product have a draft angle? What does its size depend on?
One: Why does the injection molding product have a demoulding angle?
Generally, injection molded products must be processed through corresponding molds. After an injection molded product is molded and cured, it is taken out of the mold cavity or core, commonly known as demolding. Due to molding shrinkage and other reasons, plastic parts are often wrapped around the core or trapped in the mold cavity. After the mold is opened, the mold cannot be automatically ejected, which facilitates the injection molding product to leave the mold and prevents the surface of the injection molded product from being scratched during demolding. When designing the injection mold, the inner and outer surfaces of the injection molded product must have a reasonable demolding angle along the demolding direction.
Two: Factors influencing the size of the demolding angle of injection molded products
1) The size of the demolding angle depends on the performance of the injection molded product and the geometry of the product, for example, the height or depth of the product, wall thickness and cavity surface state, such as surface roughness, processing lines, and so on.
2) Hard plastic has a larger draft angle than soft plastic;
3) The shape of the product to be injection molded is more complicated, or the plastic part with more molding holes needs a larger demolding angle;
4) If the height of the injection molded product is larger and the hole is deeper, the smaller the demoulding angle is adopted;
5) The wall thickness of the injection molded product is increased, the force of the inner hole to tighten the core is greater, and the draft angle should be larger.